Try the King lead, the one from the coil to dizzy, I had one that would
break down intermittently and under irregular circumstances, some times on a
dry day, another time on a wet day and so it went on. I have also had a
considerable success finding problems in the dark, one or two engine bays I
have looked into in the dark have looked like firework night! Also called
out to one with a switchable electronic ign kit, the points only used as a
trigger switch unless switched back to standard, this vehicle would fail
when switched to elec ign. yet run sweet when on standard, turned out (found
in the dark) that the king lead leaked sparks due to the extra current from
the elec ign.
----- Original Message -----
From: David Massey <email@example.com>
Cc: [unknown] <firstname.lastname@example.org>
Sent: Sunday, March 12, 2000 2:31 PM
Subject: TR6 running rough
> If the problem comes and goes you can rule out the timing chain. If the
> timing chain jumped it would be behaving poorly all the time.
> Intermittant symptoms suggest dirt in the fuel system, or electrical
> problems. Dirt can cause partial clogging of the fuel flow which may,
> after time break loose and you run fine again. Usually not, though, dirt
> usually causes the float valve to not close off and you run way rich.
> Another source of the problem is the fuel pump. I had a problem where my
> TR6 would stop running as though out of gas although the tank was not
> empty. If I manually operated the pump the carbs would fill (you can hear
> the gas flowing into the float chambers) and then the car would run fine.
> I eventually replaced the pump with an electric one and have had no
> ever since.
> And you might have a coil on the way out or the cap or rotor is starting
> degrade. Perhaps the wires are breaking down.
> Using the screwdriver method is not valid on Strombergs. The mixture
> adjustment is much too limited to see any change in this technique. To
> propperly adjust the carburettors requires some type of exhaust gas
> meterology (eg: gastester by Gunnison).
> Additionally, the manual is wrong about the timing. The timing should be
> set to 4 deg ATDC with the vacuum line CONNECTED. The vacuum comes from a
> special port on the carburettor that provides vacuum only at idle. Once
> off of idle the vacuum goes away and the timing reverts to normal 6 or 8
> deg BTDC. But this doesn't explain your problem. Fix this and you will
> still have the intermittant problem.
> Spindle wear only shows up at idle. Once the throttle is open the trivial
> amounts of air that leaks past will have no effect.
> Good luck
> Dave Massey
> St. Louis, MO USA
> 57 TR3 (getting O/D today)
> 71 TR6 (in storage)
> 80 TR8 (Still in re-assembly)
> Message text written by Ian
> >Hi, Listers--
> My next door neighbor recently bought a 74 TR6 and has been having
> considerable trouble with the engine breaking up. At times it runs
> and at others the only way he can make it back home is with the choke out.
> (That would seem to indicate it's running lean, no? In using the
> screwdriver method to obtain the correct mixture, the RPMs dropped
> we raised the damper on either carb. We were unable to adjust either carb
> to make the RPMs hold steady or increase.) The needles look perfect and
> were probably installed 3,000 miles ago by the PO. My neighbor has
> some of the vacuum hoses and found a few leaks but that didn't seem to
> correct the problem. The timing is set to 4 degrees ATDC with the
> distributor vacuum advance hose removed and plugged. However, there
> seem to be much vacuum on that small hose and when we re-attach it to the
> distributor, the RPMs don't change. He is currently rebuilding the
> carburetors and I was wondering what we should be looking for. The floats
> appear not to be leaking and moving freely. Is there any way to discern
> throttle spindle wear with the carbs apart? My neighbor (yes, this is a
> real person--not me) is very meticulous and has set the valves and done
> of the ignition work carefully to spec. We were starting to suspect that
> the timing chain may have jumped, but sometimes, the damn thing runs
> perfectly while we're tuning it. We shut it off, put the new air cleaners
> back on, start it up and it's rough as a cob.
> Any thoughts would be appreciated.